Aki

Aki is the youngest of Neon's sisters and a member of Uruha Oto (Sound).

Aki is a young woman who appears to be in her mid teens with short, pale blue hair with darker blue eyes. In her first appearance, she wore blue jeans along with a sleeveless white outfit along with a blue breastplate over her chest. Her madogu is contained in a choker she wears around her neck.

When her madogu was activated as she removes her outfit to topless while facing Domon from her illusions, she only wears a pair of white panties until she returns wearing her primary attire when Domon manage to broke free from her illusions. She is not seen wearing a choker after her madogu was destroyed by Domon along with her blue breastplate.

(Source: Flame of Recca Wiki)